Emblem for motor vehicle and method of making same

ABSTRACT

The present invention provides a method for making an emblem ( 10 ) for motor vehicles, said method comprising in the order given, the steps of: providing a sheet of metal ( 5 ) having opposite first ( 15 ) and second ( 16 ) major surface; applying a desired graphics design ( 2 ) on a first major surface of said sheet; cutting and forming from said metal sheet ( 5 ) an emblem ( 10 ) having a three dimensional shape; and applying a protective coating ( 1 ) on said emblem over said graphics design ( 2 ) by spray coating or powder coating whereby said protective coating ( 1 ) extends over the edge between said first and second major surface. Further provided are an emblem obtained with the method, a method of affixing the emblem to a motor vehicle and a motor vehicle having affixed to it the emblem.

FIELD OF THE INVENTION

The present invention relates to emblems having a three dimensionalshape for motor vehicles, in particular for cars, trucks and vans. Thepresent invention also relates to a method of making such emblems from ametal sheet, in particular from a sheet of aluminum. Further, theinvention relates to a method for affixing the emblem to a motor vehicleand to a motor vehicle having the emblem affixed to it.

BACKGROUND OF THE INVENTION

Motor vehicles such as cars, trucks and vans are commonly provided withemblems carrying a brand or logo of the manufacturer of the motorvehicle. Such emblems may be of a three dimensional shape and aretypically attached to the exterior of the body of the motor vehicle. Forexample, the emblem may have an oval and shallow concave shape such asfor example the emblem used by Ford Company. Such an emblem is attachedto a motor vehicle, for example by means of glue or an adhesive tape,with its concave side facing towards the body of the motor vehicle. Theother side, i.e. the convex side of shape then forms the visible part ofthe emblem when attached to the body of the motor vehicle. This visibleside of the emblem is typically provided with a graphic design such asfor example a colored layer or the printing of a brand. A protectivelayer typically overlays the graphic design.

A method of forming car emblems is for example disclosed in U.S. Pat.No. 3,773,568. According to the method there disclosed, a sheet ofaluminum is first treated and subsequently provided with a coloredresinous enamel image and a protective epoxy coating. Thereafter thesheet may be subjected to further mechanical operations to form thedesired final emblem. It has however been found that such emblems whenformed into three dimensional shapes suffer from a poor corrosionresistance. Furthermore, small cracks, so called micro-cracks, wereobserved in the protective coating. As a result, the emblem may looseits good appearance during the lifetime of the motor vehicle, which isparticularly a concern with cars and vans.

SUMMARY OF THE INVENTION

The present invention provides a method for making an emblem (10) formotor vehicles, said method comprising in the order given, the steps of:

-   -   providing a sheet of metal (5) having opposite first (15) and        second (16) major surface;    -   applying a desired graphics design (2) on a first major surface        of said sheet;    -   cutting and forming from said metal sheet (5) an emblem (10)        having a three dimensional shape; and    -   applying a protective coating (1) on said emblem over said        graphics design (2) by spray coating or powder coating whereby        said protective coating (1) extends over the edge between said        first and second major surface.

Accelerated corrosion tests indicate that when the emblem is formedaccording to the method of the invention, the emblem will likely havelittle or no corrosion over the lifetime of the motor vehicle andsubstantially no cracks were observed in the protective coating. Inparticular, by applying the protective coating after cutting and formingof the emblem into the desired three dimensional shape, micro cracks canbe avoided. Moreover, by using spray coating or powder coating to applythe protective coating, the edges, which typically correspond to thethickness of the initial metal sheet, between the first and second majorsurface are provided with the protective coating as well. It is believedthat this provides for a superior corrosion resistance of the metalemblem.

Thus, in accordance with a further aspect of the present invention thereis also provided an emblem (10) having a three dimensional shape forattaching to a motor vehicle, said emblem (10) being made of metal andhaving a first major surface (15) and an opposite second major surface(16), said first major surface (15) having a graphics design (2) formingthe visible part of said emblem (10) when attached to the motor vehicle,wherein said first major surface (15) comprises a protective coating (1)on said graphics design (2) and wherein said protective coating (1)extends over the edge (12) between said first and second major surfaces.

In another aspect, the present invention relates to a method ofproviding a motor vehicle with a three dimensional emblem, comprisingthe steps of affixing the emblem of the invention to the exterior bodyof said motor vehicle.

Still further, the invention provides a motor vehicle comprising thethree dimensional emblem of the invention affixed to its exterior body.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is further described by way of reference to the followingdrawings which are merely intended to illustrate the invention and whichshould not be taken to limit the invention in any way.

FIG. 1 shows a schematic drawing of an embodiment of a three dimensionalemblem according to the invention.

FIG. 2 shows a cross-section along the line A-A of the emblem of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the method of making the 3-D emblem, a metal sheet isfirst provided. The metal sheet can be any metal as can be used formaking emblems for motor vehicles, in particular cars. Typically, themetal sheet will be a sheet of aluminum but other metal sheets such as asteel sheet may also be used. The thickness of the sheet will generallybe between 0.5 mm and 1 mm. The sheet may be first treated so as toimprove the adhesions of coatings, in particular paint coatings thereto.For example, when the sheet is made of aluminum, it may be treated asdisclosed in U.S. Pat. No. 3,773,568.

To a first major side of the metal sheet is then applied a graphicsdesign. The graphic design may include letters, numbers or any otherindicia such as images and icons. The graphics design may be comprisedof a single layer or multiple layers. Typically, the layer or layersmaking up the graphics design will comprise dyes or color pigments.Also, the layer or layers of the graphics design will typically includeone or more polymers such as for example an alkyd based polymer, anacrylic polymer or a polyurethane. The graphics design may be applied byany desired technique for applying graphics designs. For example, aprinted design may be applied by screen printing, pad or tampon printingor etching. Before the application of the layers making up the graphicsdesign, it will generally be preferred to apply one or more primers thatwill improve the adhesion of the graphics design to the metal sheet.

Subsequent to the application of the graphic design the emblem is formedout of the metal sheet by cutting and forming it in the desired 3Dshape. For example, with an appropriate tool, an oval and convex emblem(10) as shown in FIG. 1 may be cut and formed out of the metal sheetwhereby the graphics design is on the convex side of the emblem. Whenviewed from the opposite side, the emblem is concave. Typically theconcave is a shallow concave, for example a depth of between 1 and 10mm. The emblem may also be further embossed. Such embossing can becarried out before or after cutting and forming of the emblem from themetal sheet. Preferably however, embossing is carried out simultaneouslywith forming and cutting of the emblem from the metal sheet. In order toprotect the graphic design during handling and forming of a 3D shape forthe emblem from the metal sheet, a temporary protective film may belaminated over the graphic design prior to forming and cutting of theemblem from the metal sheet. For this purpose, one can use for example apolyethylene based film which can be cold laminated to the metal sheet.After the cutting and forming operation, the temporary protective filmneeds to be removed.

Following forming and cutting of the emblem, the emblem is provided witha protective coating over the graphics design. The protective coating isgenerally clear and transparent and is generally comprised of a resin.The protective coating may also be tinted. Typically, a hard curableresin such as a curable acrylic resin or an epoxy resin is used for theprotective coating. The thickness of the protective coating willgenerally be between 30 μm and 150 μm, preferably between 50 μm and 100μm. The protective coating is applied by spray coating or powdercoating.

When spray coating is applied, the coating composition for theprotective layer may comprise the resin dissolved in a solvent oralternatively, the resin for the protective coating may be a hot meltresin in which case a solvent can be avoided. During spray coating, theemblem is supported from its backside, i.e. the side opposite to theside bearing the graphic design. Spraying may be carried out manually orthrough the use of a robotic sprayer. The emblem should be sprayed insuch a way as to cover the complete graphic design. Also spraying shouldextend over the edges between the first major surface of the emblemcarrying the design and the second major surface forming the backside ofthe emblem. Thus, as can be seen in FIG. 2, the protective coating willthereby extend over edge (12) between the convex and concave side of theemblem (10).

In accordance with a preferred embodiment, the protective coating isapplied by powder coating. Powder coating is an electrostatic spraycoating process wherein a coating powder is dispersed in an air streamand passed through a corona discharge field where the powder particlesacquire electrostatic charge. The particles are attracted to anddeposited on a grounded object to be coated. Thus, by grounding theemblem, it can be powder coated with the protective coating. Powdercoating of the emblem typically also involves melting or fusing of thepowder particles by heating so that the powder particles form a film orcoating. Heating is typically carried out using an oven, e.g. aconvection oven. Alternative heating techniques may include, infraredheating, resistance heating and induction heating methods. To coat theemblem using powder coating, the emblem is placed on a jig or isotherwise supported from its backside whereby care is taken not to coverthe edges of the emblem between the first and second major surface ofthe emblem. The emblem is then electrostatically sprayed with a powdercoating for the protective layer whereby the powder is deposited on thefirst major surface of the emblem. Also, it has been found that thepowder also deposits at edge (12) between the opposite first and secondmajor surfaces of the emblem (10). Electrostatic spraying is generallycarried out at room temperature. After spraying, the emblem is subjectedto heat by for example placing it in an oven to thereby cause the powderparticles to melt so as to form a film of protective coating.

Using the method of the invention, an emblem as shown in FIGS. 1 and 2can be formed. As shown in FIG. 1, the emblem (10) has an oval shape andas can be appreciated from the cross-section shown in FIG. 2, the emblem(10) is convex. The first major surface (15) is at the convex side ofemblem (10) and opposite thereto is the second major surface (16) at theconcave side of emblem (10). The depth of the concave of emblem (10) istypically between 1 mm and 10 mm. Between the first and second majorsurface is edge (12) which connects the opposite major surfaces to eachother. The edge (12) typically corresponds to the thickness of the metalsheet used to form the emblem. Emblem (10) further includes an embossingas shown by numeral (3). On the first major surface of the metal sheet(5), there is provided a graphics design formed by a printed layer (2)and overlaying the printed layer (2) there is a protective coating (1).As seen in FIG. 2, the protective coating (1) extends over the edge (12)between first and second major surfaces of the emblem (10). Theprotective coating (1) may also extend over the part of the second majorsurface (16).

The emblem, for example the emblem (10) of FIG. 1 may be affixed to theexterior body of a motor vehicle, in particular a car or a van. Theexterior body of motor vehicle may be adapted for receiving andpositioning of the emblem. For example, with emblem (10), the exteriorbody may comprise an elliptical groove or recess corresponding to thedimensions of the oval shape of emblem (10). Alternatively, the exteriorbody may comprise a raised portion that corresponds to the dimensions ofthe concave side of emblem (10) so that emblem (10) can be placed overthe raised portion. The emblem will typically be affixed to the motorvehicles exterior body by means of a glue, for example a pressuresensitive adhesive or a hot melt glue, or by using an adhesive tape suchas for example a double coated acrylic foam tape.

The following examples further illustrate the invention and are notintended to limit the invention in any way.

EXAMPLES

Test Method—Corrosion Resistance

Completed emblem was exposed to a thermal cycle (10 cycles) incombination with a Copper-Accelerated Acetic Acid-Salt treatment. Thiscorresponds to test method ASTM (American Society for Testing andMaterials) method # B 368-97. After the test was completed, the emblemswas examined visually to observe whether corrosion was present,particularly corrosion visibly starting from the emblem edges. Corrosionabsence or presence was noted. Corrosion that occurred in areas on theback of the emblem that were not protected was discounted.

Top surfaces of the emblems were also evaluated for the presence ofcracks and corrosion.

Example 1

A bright-finished aluminum sheet (0.65 mm thickness) having thedimensions of 173 cm×457 mm was obtained from Baco Metal Centres(Tipton, UK). The aluminum sheet was degreased and activated by passingthrough a caustic soda bath, then rinsed with water and air dried. Onesurface of the aluminum sheet was then primed by applying a coating of asolvent-based terpolymer of polyvinyl butyral, polyvinyl alcohol, andpolyvinylacetate available as SVP2003 from Development Associates Inc.(North Kingstown, Conn., USA.) in a thickness of approximately 2-3 μm.The primer coating was then cured at a temperature of 60° C. for about 1minute.

The primed surface of the aluminum sheet was then printed employing ascreen printing process using a blue alkyd-based screen-printing ink(available as product number SSTL86740 from Gibbon Inks and CoatingsWimbledon, UK) in the shape of a graphic representing the logo design ofthe Ford Motor Company. The sheet was printed in a fashion to give onerow of six separate graphic areas corresponding with the positions fromwhich emblems were to be finally cut. The screen-printing ink was driedin a forced-air oven at a temperature 160° C. for 20 minutes.

A blue-tinted transparent polyethylene-based polymeric film having athickness of 0.05 mm was cold laminated over the surface of the graphicand covering the entire sheet for temporary protection of the graphicfrom scratching during cutting and forming operations.

The six individual emblems were then cut out of the sheet in the shapeof an oval having a length of approximately 120 mm long and 55 mm wide,each bearing the Ford Motor Company logo.

The largely flat pieces were then formed into a shallow convex shapeusing a cold-forming tool. At the same time the areas corresponding tothe Ford logo design were embossed. The temporary protectivepolyethylene-based film was then removed from the graphic-bearingsurface.

The pieces were then mounted individually on a support rod or jig andfinally spray-coated using a robotic sprayer to provide a continuouscoating covering the top surface of the emblem bearing the printing, thecut edges of the emblems and portions of the back side of the emblem notmasked by the jig. The coating comprised a solvent-based one packacrylic melamine obtained as RK-O121 B Super Mar from DuPont(Wilmington, Del., US). The clear, colorless coating was then dried for30 minutes at 140° C. in a forced air oven to provide a dry coatingthickness of approximately 50 μm.

The completed emblem was then tested for corrosion resistance asdescribed above. Test results showed that no corrosion was present atthe edges or on the top surface of the emblem. Additionally, no evidenceof cracks on the printed surface could be observed.

Example 2

Example 1 was repeated with the exception that the final protectivecoating was applied to the printed and formed emblem employingpowder-coating techniques.

The individual emblems were supported on jigs on a continuous transportbelt. The emblems were then passed through a powder coating zone where acontrolled deposition of electrostatic charged powder paint particlestook place. The emblems were fully coated with powder with the exceptionof the small area on the back of the emblem masked by the supportingjig. The powder coating comprised a polyurethane/epoxy.

The powder-coated emblems were then passed through an oven held at 200°C. for 5 minutes to cure the powder coating and bond it to the emblem toform a continuous protective coating. The thickness of the protectivecoating was approximately 100 μm.

Completed emblems were corrosion tested and inspected as described underthe test method above. Test results showed that no corrosion was presentat the edges or on the top surface. Additionally, no evidence of crackson the printed surface could be found.

1. Method for making an emblem for motor vehicles, said methodcomprising in the order given: providing a sheet of metal havingopposite first and second major surface; providing a desired graphicsdesign on a first major surface of said sheet; cutting and forming fromsaid sheet an emblem having a three dimensional shape; and applying aprotective coating on said emblem over said graphics design by spraycoating or powder coating whereby said protective coating extends overthe edge between said first and second major surface.
 2. Methodaccording to claim 1 wherein prior to the application of said graphicsdesign, a prime coating is applied to said first major surface of saidmetal sheet.
 3. Method according to claim 1 wherein said threedimensional shape of said emblem comprises a convex side, whereby theconvex side is formed by said first major surface.
 4. Method accordingto claim 1 wherein prior to, during or after forming said one or moreemblems, a design is embossed on said first major surface of said metalsheet.
 5. Method according to claim 1 wherein said metal is selectedfrom aluminum and steel.
 6. Emblem having a three dimensional shape forattaching to a motor vehicle, said emblem being made of metal and havinga first major surface and an opposite second major surface, said firstmajor surface having a graphics design and forming the visible part ofsaid emblem when attached to the motor vehicle, wherein said first majorsurface comprises a protective coating on said graphics design andwherein said protective coating extends over the edge between said firstand second major surfaces.
 7. Emblem according to claim 6 wherein saidemblem comprises a convex side whereby the convex side is formed by saidfirst major surface.
 8. Emblem according to claim 7 wherein said metalis aluminum or steel.
 9. Method of providing a motor vehicle with athree dimensional emblem, comprising affixing the emblem according toclaim 6 to the exterior body of the motor vehicle.
 10. Motor vehiclecomprising a three dimensional emblem according to claim 6 affixed toits exterior body.
 11. Method according to claim 2 wherein prior to,during or after forming said one or more emblems, a design is embossedon said first major surface of said metal sheet.
 12. Method according toclaim 3 wherein prior to, during or after forming said one or moreemblems, a design is embossed on said first major surface of said metalsheet.
 13. Method according to claim 2 wherein said metal is selectedfrom aluminum and steel.
 14. Method according to claim 3 wherein saidmetal is selected from aluminum and steel.
 15. Method according to claim4 wherein said metal is selected from aluminum and steel.
 16. Method ofproviding a motor vehicle with a three dimensional emblem, comprisingaffixing the emblem according to claim 7 to the exterior body of themotor vehicle.
 17. Method of providing a motor vehicle with a threedimensional emblem, comprising affixing the emblem according to claim 8to the exterior body of the motor vehicle.
 18. Motor vehicle comprisinga three dimensional emblem according to claim 7 affixed to its exteriorbody.
 19. Motor vehicle comprising a three dimensional emblem accordingto claim 8 affixed to its exterior body.